Positioner for calendar dial in timepiece

ABSTRACT

The positioner for the claendar dial fitted in a calendar timepiece is adapted to keep the dial in its working position in a highly stabilized manner. Since the idle distance between the dial plate and the star wheel of the timepiece varies on account of unfavorable deflections or deformations of the dial plate, the stabilizing positioner comprises a resilient ring made from a plate the inner periphery of which abutts upon a first mounting shoulder formed on the cannon wheel of the timepiece and the outer periphery of which abutts on a second mounting shoulder formed on the star wheel.

United States Patent Miyasaka et al.

[54] POSITIONER FOR CALENDAR DIAL IN TIMEPIECE [72] Inventors: Kenjl Mlyaslka; Ynsuakl Nakeyama, both of Tokyo, Japan [73] Anuignec: Citizen Watch Co., Ltd., Toltyo, Japan [22] filed: June 25, 1970 [2i] Appl. No.: 49,722

[58] Field oiSearchm' ..58/4, 5,58

[ 51 May 2, 1972 [56] References Cited UNITED STATES PATENTS 2,582,879 111952 Meyer ..ss/ss [57] ABSTRACT The positioner for the claendar dial fitted in a calendar timepiece is adapted to keep the dial in its working position in a highly stabilized manner. Since the idle distance between the dial plate and the star wheel of the timepiece varies on account of unfavorable deflections or deformations of the dial plate, the stabilizing positioner comprises a resilient ring made from a plate the inner periphery of which abutts upon a first mounting shoulder formed on the cannon wheel of the timepiece and the outer periphery of which abutts on a second mounting shoulder formed on the star wheel.

PATENTEDMAY 21972 3,659,412

SHEET 3 (IF 3 POSITIONER FOR CALENDAR DIAL IN TIMEPIECE This invention relates generally to calendar timepieces. More specifically, it is concerned with improvements, in the positioner for the calendar dial fitted in the timepieceof the above kind, adapted for keeping the said dial in its working position in a highly stabilized and secure manner.

As the stabilizing means serving for the above service in the calendar timepiece, a dial washer is used, said washer being positioned between the day star wheel and the dial plate. The day calendar dial is rigidly attached concentrically to said star wheel and said dial washer urges the star wheel against the plate, so as to control axial idle movement of the star wheel.

In the conventional arrangement so far described, the idle distance between the dial plate and the star wheel varies on account of unavoidable deflection or the like deformation of the dial.

Under extreme circumstances where the amount of said dial deformation amounts to an appreciable value, the cannon or hour wheel and the minute wheel may frequently be disengaged from their meshing condition, which constitutes a substantial drawback inherent in the conventional art under consideration.

In the case of dismantling of time-indicating hands, especially hour hand, a considerable amount of manual force will be transmitted through the hour wheel to the dial which is thus subjected to a considerable deformation, thus providing a further drawback.

On the other hand, the range of the unavoidable axial idle movement of the star wheel can be determined only after fitting the dial in position. If, in this case, the said idling range be found to reside outside of the prescribed allowable one, the dial washer should be subjected to manual adjustment in its elasticity, which constitutes still a further conventional drawback.

It is a main object of the present invention to provide a stabilizing positioner for the star wheel, capable of obviating the aforementioned several conventional drawbacks.

It is a still further object of the invention to provide a positioner of the above kind, capable of providing'a possibility for determining the amount of said kind of axial idle movability of the star wheel, irrespective of the occasional positioning of the dial plate.

These and further objects, features and advantages of the invention will become more apparent when read the following detailed description of the invention by reference to the accompanying drawings illustrative of substantially two embodiments of the invention.

In the drawings:

FIG. 1 is an axially sectional view of essential embodiment of the invention.

FIG. 2 is a plan view of a stabilizer spring employed in the first embodiment shown in FIG. 1.

FIG. 3 is a sectional view taken on the section line 3-3 shown in FIG. 2.

FIGS. 4-9 are similar views to FIG. 2, illustrative of several modifications from the positioner spring shown therein.

FIG. is a plan view of a timepiece movement embodying the mechanism shown in FIG. 1, being, however drawn on somewhat reduced scale.

FIG. 11 is a similar view to FIG. 1, showing, however, a second embodiment of the invention.

Referring now to FIG. 1 of the accompanying drawings, numeral l0 denotes a conventional center wheel to which a cannon pinion ll of the conventional design is attached fricparts of a first tionally. Numeral 12 denotes a conventional fourth pinion.

caulking or the like conventional fixing measure, said star wheel being formed with a concentric and stepped recess 16a for stabilizedly positioning therein a disc spring 18. Within said recess 160, there is formed a ring shoulder 16b on which the outer peripheral edge of positioner spring 18 abuts under pressure. The upper side wall 14b of said ring groove 14a constitutes a ring shoulder on which the inner peripheral edge of positioner spring I8 abuts again under pressure, the urging pressure exerted by the spring directing downwards relative to the star wheel 16. As seen from FIGS. 2-3 the spring is made from a plate and has a flattened circular configuration in its plan view, a pair of diametrally opposite ears 18a and 18b being formed on the concavely curved and flattened sides of the spring 18. The mounting shoulders 14b and 16b are positioned substantially at a same level when seen in FIG. 1 for providing the axially directing thrust.

Although not specifically shown, the day disc 15 is fixedly attached to the conventional plate 20 by means of set screws, not shown.

Numeral 19, only partially shown, represents a conventional time-indicating dial. The day dial stabilizing ring spring 18 has a plan configuration shown in FIG. 2, a sectional view thereof being shown in FIG. 3. When it is desired to dismantle this ring from position, a diametrally outwardly directing manual force is applied onto one of these cars from outside by means of a proper tool such as, for instance, a pincette, so as to expand the ring spring outwardly from upper or lower in FIG. 2. The pincette can engage the opposed recesses on opposite sides of the ear 18a or 18b.

The height of the mounting shoulder 16b formed in the day star wheel 16 is so selected that the plate-like ring spring 18 when positioned in position as shown may serve well to exert an urging pressure upon the day star wheel 16 which is thus kept in pressurized axial engagement with the cannon wheel 14.

Otherwise possible and excess axial movement of cannon wheel 14 is limited by the plate 20, on the one hand, and by the reduced extension lSa of day disc 15, on the other, so that an unintentional disengagement of cannon wheel from meshing with minute pinion 21 may be positively prevented.

By the stabilized pressure contact of the day star wheel 16 with cannon wheel 14 under the influence of the stabilizer spring I8, the amount of unintentional axial movement of day dial l7 and day star wheel 16 is generally and substantially equal to that of the cannon wheel 14, under normal working position of the timepiece movement without being influenced by sudden and substantial outside shocks. Should the aforementioned pressure engagement be absent, resulting in a freely and axially movable arrangement of the day star wheel 16, the dimensional allowance for said movability must be substantially larger than the case of the said pressure-engaging arrangement of said star wheel wherein the axial movability thereof becomes a substantial amount and the dial 19 may be positioned at a considerably lower position when seen in FIG. I, thus providing a substantially reduced overall height of the timepiece movement.

When dismantling the time-indicating hands, not shown, from position as met in the overhauling of the movement, an upward movement of cannon wheel 14 will be frequently invited. But, as was referred to hereinbefore, this kind of axial movability is limited to a smallest minimum by contact of the cannon wheel with the disc 15. Since the axaial movability of day star wheel 16 is determined independently of the dial plate 19, the allowable amount of axial movement of these elements may be observed easily without fitting the dial plate in position. In the case of repair job, the day calendar dial and the cannon wheel could not drop out from position after removal of the dial plate 19. Since the day star wheel 16 is subjected to a lateral mechanical force exerted by a conventional jumper lever 28, (see, FIG. 10) the hour hand, not shown, is prevented from being liable to oscillate by virtue of the presence of unavoidable backlash appearing between the meshing cannon wheel 14 and minute wheel I3.

The ring spring 18 used for stabilizing the day calendar dial is, as was referred to hereinabove, a plate and there is no difference between the front and the back surface, which is highly convenient in the assembly thereof, because there is no necessity for identifying either desired surface.

In FIGS. 4-9, several modifications from the day dial stabilizing spring 18 shown in FIGS. 2-3, at 22-27, respectively.

In the modification of the positioner spring shown at 22 in FIG. 4, the spring is formed with convexedly projecting projections 22a and 22b which serve substantially for the same purpose as performed by the ears 18a and 18b shown in FIG. 2

In a still modified form in FIG. 5, the spring shown at 23 is formed with similar oppositely directing convex projections 23a and 23b. The purpose of the provision of these projections is similar to those described in connection with FIGS. 24. However, in the present embodiments shown in FIG. 5, the ring spring is fonned into an open shape instead of the closed one which has been shown and described hereinbefore.

In a still further modified positioner spring shown at 24 in FIG. 6, the overall configuration is somewhat different from the foregoing model shown in FIG. 5.

It will be seen that this modification shown in FIG. 6 is formed into an open ring spring, there being several inwardly directing projections shown at 24a, 24b, 24c and 24d, as shown. These projections serve as the ears 18a, 18b, shown in FIG. 2, regardless of difference in the configuration of each of these projections.

In FIG. 7, a still further modified configuration of the positioner spring is shown at 25, which has been formed into a trilobe.

The parts shown at 25a, 25b and 25:: serve as ears shown in FIG. .2 and described in connection therewith, regardless of substantial difference in their configurations.

When dismontling this spring from position, one of these projections, for instance, that shown at 25a, is manipulated by means of a proper tool so as to disengage only a part of the whole ring from position.

In these FIGS. 2-7, chain dotted line double ring denotes in an imaginary and schematic way the aforementioned in a mounting shoulder 14b.

A still further modified positional spring is shown in FIG. 8 at 26. This positional spring 26 comprises a completely closed circular ring portion 260 which is rigidly attached outside circular element 26b and 26c arranged oppositely to each other.

Said inner elements 26b and 26c are connected rigidly with the outer ring portion 26a by connecting portions 26d and 26e, respectively. In dismantling service, these connecting portions 26d and 26e serve as the ears shown in FIG. 2 at 18a and 18b, respectively, irrespective of substantial difference in their configuration.

A still further modified positional spring shown at 27 in FIG. 9 has been shaped into a closed rectangular ring which has several portions shown at 27a, 27b, 27c and 27d, serving each as the ear 18a or 18b shown in FIG. 2.

In these FIGS. 8 and 9, the inner mounting shoulder 14b is also shown by chain dotted lines.

In the general arrangement shown in FIG. illustrative of a timepiece movement including the mechanism shown in FIG.

1, the relative position of the said mechanism to several known parts is illustrated.

In this figure, numeral 29 denotes a conventional winding stem; 30 a winding pinion; 31 a calendar feed wheel; 32 a date calendar feed pawl wheel; 33 a day calendar feed pawl wheel; 34 an intermediate wheel; 35 a date calendar dial; 36 a jumper for the latter; and 37 a day jumper spring. Main working parts shown in FIG. 1 are also shown by respective same reference numerals. I

In the second embodiment shown in FIG. 11, the day star wheel shown at 16 is formed with a ring groove 16b formed within the area of the concentric stepped recess 16d, the lower side wall of this groove serving as the outer mounting shoulder in the similar sense referred to hereinbefore in connection with that shown at 16b in FIG. I.

ther parts are substantially similar in their design and function and thus denoted by respective same reference numerals, each attached, however, with a prime. The features of the both mounting shoulders 14b and 16b being designed and arranged in the similar manner as referred to, as will be easily supposed from FIG. 11.

As will be clearly understood from the foregoing description by consultation with the drawings, the positioner spring is kept in engaging position with both cannon wheel and day star wheel so as to provide a resilient axial thrust directing towards the plate upon the cannon wheel, by virtue of axial flexibility of the positioner spring which has been placed in position under slight tension.

On the other hand, a part of the cannon wheel is positioned between the plate and the mounting plate so as to be subjected therebetween to a limitation in its idle axial movement, as was referred to herein-before. Since the star wheel is placed in position under resilient pressure exerted by jumper lever and the positioner spring is kept also in resilient pressure engagement with both cannon wheel and day star wheel, the cannon wheel is thus prevented from otherwise possible slight idle rotation, thereby an fluctuative movement of the hour hand being positively prevented.

It will be clear that the inventive features are also applicable to the date calendar mechanism, although not shown and described only for simplicity.

The embodiments of the invention in which an exclusive property or priviledge is claimed are defined as follows:

I. In a calendar timepiece movement comprising a calendar dial, a star wheel made rigid with said dial and arranged to be driven by a conventional gear train of said movement for feeding said dial, a cannon wheel mounted concentrially with said star wheel, a pivotable jumper lever arranged to cooperate with said star wheel by exerting a resilient pressure thereupon for provisionally positioning the latter, and a mounting plate fixedly mounted on the conventional plate of the movement, the improvement consists in that a positioner spring for said calendar dial is inserted between the cannon wheel and the star wheel, the positioner spring comprises a resilient ring made from a plate, the inside periphery of said ring spring abutting upon a first mounting shoulder formed on the cannon wheel and the outer periphery of the same ring spring abutting on a second mounting shoulder formed on the star wheel. 

1. In a calendar timepiece movement comprising a calendar dial, a star wheel made rigid with said dial and arranged to be driven by a conventional gear train of said movement for feeding said dial, a cannon wheel mounted concentrially with said star wheel, a pivotable jumper lever arranged to cooperate with said star wheel by exerting a resilient pressure thereupon for provisionally positioning the latter, and a mounting plate fixedly mounted on the conventional plate of the movement, the improvement consists in that a positioner spring for said calendar dial is inserted between the cannon wheel and the star wheel, the positioner spring comprises a resilient ring made from a plate, the inside periphery Of said ring spring abutting upon a first mounting shoulder formed on the cannon wheel and the outer periphery of the same ring spring abutting on a second mounting shoulder formed on the star wheel. 